The emergence of new viral diseases such as HCV, SARS, West Nile virus, H1N1 influenza, increased threat of bioterrorism using smallpox and appearance of new viral strains resistant to existing drugs warrants development of new medications. The goal of this proposal is to discover new antiviral candidates to treat such diseases by modifying a lead carbocyclic nucleoside analog. New analogs synthesized will be tested for antiviral activity against a wide array of viruses. PUBLIC HEALTH RELEVANCE: The goal of this proposal is to discover new antiviral candidates to treat new viral diseases such as HCV, SARS, West Nile virus, H1N1 influenza, and bioterrorism agent smallpox. The proposed research project also focuses on the development of new medications to viral strains resistant to existing drugs by modifying a lead carbocyclic nucleoside analog.